The present invention relates to treatment accessories for an endoscope. During use, a treatment accessory is inserted in a forceps channel of the endoscope; however, as the treatment accessory is being inserted through the forceps channel of the endoscope, before the distal end of the treatment accessory appears in an observing field of the endoscope, the distal end will have already been extended from the end of the forceps channel by a certain amount. Since a treatment device such as a forceps device is connected to the distal end of the treatment accessory, if the treatment accessory is pushed and extended from the forceps channel excessively, the treatment accessory may damage a mucous layer inside a human cavity.
In a conventional treatment accessory, the above problem is prevented, by providing an index mark on a manipulation portion of the treatment accessory such that the extending amount of the treatment accessory is recognized. An example of such a treatment accessory is disclosed in JP Utility Model Provisional Publication SHO 52-158589, and JP Utility Model Provisional Publication SHO 61-203009.
However, since the viscera (human tissue) or the like are continuously moving, once the affected part comes into the observing field, it is preferable that the treatment accessory be pushed quickly through the forceps channel.
In this case, even though an index mark is formed on the treatment accessory, in a quick insertion, the treatment accessory may be inserted more than intended and the viscera (human tissue) may be damaged.
Further, since there are various endoscopes having different lengths of forceps channels, the treatment accessory is generally formed to have a length that is appropriate for use in an endoscope having a forceps channel of a particular length. Accordingly, a plurality of treatment accessories which have different lengths must be available.
However, having a plurality of treatment accessories for endoscopes having different forceps channel lengths is not economical. A long treatment accessory may also be used for an endoscope having a shorter forceps channel, however, if the treatment accessory is relatively long with respect to the forceps channel, there is a risk that when the treatment accessory is inserted in the forceps channel, the treatment accessory may be inserted too far and may damage tissue inside a body.
Further to the above, the treatment accessory should be removed from the forceps channel as soon as the affected part has been treated. However, while the treatment accessory is being removed (pulled out of the forceps channel), it is difficult to judge the length of the treatment accessory, such that, if the treatment device is removed quickly, the flexible shaft may jump on exiting the forceps channel such that a collected sample or other substance may be dislodged and sprinkled around the room.